Method and apparatus for determining endpoint of semiconductor element fabricating process and method and apparatus for processing member to be processed

• US 20030043383A1
• Filed: 09/06/2001
• Published: 03/06/2003
• Est. Priority Date: 09/06/2001
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Fujii, Takashi, Yoshigai, Motohiko, Usui, Tatehito, Yamamoto, Hideyuki, Kaji, Tetsunori
• Granted Patent: US 6,903,826 B2
• Time in Patent Office: Days
• US Class Current: 356/504
• CPC Class Codes: G01B 11/0675 using interferometry
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

Standard patterns of differential values of interference light that correspond to a predetermined step height of the first material being processed and standard patterns of differential values of interference light that correspond to a predetermined remaining mask layer thickness of the material are set. These standard patterns use wavelengths as parameters. Then, the intensities of interference light of multiple wavelengths are measured for a second material that has the same structure as the first material. Actual patterns with wavelength as parameter are determined from differential values of the measured interference light intensities. Based on the standard patterns and the actual patterns of the differential values, the step height and the remaining mask layer thickness of the second material are determined.

Claims

1. A method of measuring a film process quantity in a semiconductor device manufacturing process, comprising:

a) a step of setting standard patterns of differential values of interference light from a first material to be processed (4, 5, etc.) that correspond to a predetermined film process quantity of the first material, the standard patterns using the wavelength as a parameter;

b) a step of measuring intensities of interference light of multiple wavelengths from a second material being processed (4, 5, etc.) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter; and

c) a step of determining a film process quantity (43) of the second material based on the standard patterns of the first material and the actual patterns.

2. A method of measuring a film process quantity in a semiconductor device manufacturing process, comprising:

a) a step of setting standard patterns of differential values of interference light from a first material to be processed (4, 5, etc.) that correspond to a predetermined film process quantity of the first material, the standard patterns using the wavelength as a parameter;

b) a step of measuring intensities of interference light of multiple wavelengths from a second material being processed (4, 5, etc.) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

c) a step of determining a film process quantity (43) of the second material based on the standard patterns of the first material and the actual patterns; and

d) a step of performing processing by changing a process condition when the film process quantity of the second material reaches a predetermined value.

3. A method of measuring an etch quantity of a material being processed, comprising:

a) a step (400) of setting standard patterns (P_S) of differential values of interference light from a first material to be processed (4) that correspond to a predetermined etch quantity of the first material including a mask layer (41), the standard patterns using the wavelength as a parameter;

b) a step (420) of setting standard patterns (P_M) of differential values of interference light from the mask layer of the first material that correspond to a predetermined etch quantity of the mask layer, the standard patterns using the wavelength as a parameter;

c) a step (402-408, 424-428) of measuring intensities of interference light of multiple wavelengths from a second material being processed (4) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter; and

d) a step (410, 430, 412) of determining an etch quantity (44) of the second material based on the standard patterns of the first material, the standard patterns (P_S and P_M) of the mask layer, and the actual patterns.

4. A method of measuring an etch quantity of a material being processed, comprising:

a) a step (500) of setting standard patterns (P_S) of differential values of interference light from a first material to be processed (4) that correspond to each of a plurality of predetermined etch quantities of the first material including a mask layer (41), the standard patterns using the wavelength as a parameter;

b) a step (520) of setting standard patterns (P_M) of differential values of interference light from the mask layer of the first material that correspond to each of a plurality of predetermined etch quantities of the mask layer, the standard patterns using the wavelength as a parameter;

c) a step (502-508, 524-528) of measuring intensities of interference light of multiple wavelengths from a second material being processed (4) of the same structure as the first material and determining actual patterns o f differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

d) a step (510-515, 530-535) of determining an etch quantity of the second material based on the standard patterns of the first material, the standard patterns (P_S and P_M) of the mask layer, and the actual patterns; and

e) a step (516, 536) of determining an etch quantity (S, M) of the second material at a present point in time by a recurrent analysis using the old etch quantity of the second material obtained by step d).

5. A method of measuring an etch quantity of a material being processed, comprising:

a) a step (600) of setting standard patterns (P_Z) of differential values of interference light from a first material to be processed (5) that correspond to each of a plurality of predetermined etch quantities of the first material, the standard patterns using the wavelength as a parameter;

b) a step (602-608) of measuring intensities of interference light of multiple wavelengths from a second material being processed (5) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

c) a step (610-615) of determining an etch quantity of the second material based on the standard patterns of the first material and the actual patterns; and

e) a step (616, 618) of estimating a time at which the etch quantity of the second material reaches a target value, by a recurrent analysis using the old etch quantity of the second material obtained by step c).

6. The etch quantity measuring method according to claim 5, further comprising:

a step of determining an etch rate by a recurrent analysis using the old etch quantity of the second material obtained by step c).

7. The etch quantity measuring method according to claim 5, further comprising:

a step of determining an initial thickness of the second material by a recurrent analysis using the old etch quantity of the second material obtained by step c).

8. The etch quantity measuring method according to claim 5, further comprising:

a step of determining an initial thickness and a remaining thickness of the second material by a recurrent analysis using the old etch quantity of the second material obtained by step c); and

a step of determining an etch depth of the second material based on the initial thickness and the remaining thickness of the second material obtained.

9. A method of processing a material in semiconductor devices having a plurality of stacked films, comprising:

a step of measuring a remaining thickness of the material being processed; and

a step of performing etching by changing an etching condition when the remaining thickness reaches a predetermined value.

10. A method of etching a material in semiconductor devices having a plurality of stacked films, the material being formed over an underlying film having parts of different thicknesses, the etching method comprising:

a step of measuring a remaining thickness of the material formed over the thick part of the underlying film; and

a step of controlling the etching according to the measured remaining thickness of the material.

11. The etching method according to claim 10, further comprising:

a step of performing etching by changing an etching condition when the measured remaining thickness of the material reaches a predetermined value.

12. A method of etching a material in semiconductor devices having a plurality of stacked films, comprising:

a) a step (800-801) of setting standard patterns (P_Z) of differential values of interference light from a first material to be processed (7) that correspond to a plurality of predetermined etch quantities of the first material, the standard patterns using the wavelength as a parameter;

b) a step (802-808) of measuring intensities of interference light of multiple wavelengths from a second material being processed (7) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

c) a step (810-815) of determining an etch quantity of the second material based on the standard patterns of the first material and the actual patterns;

d) a step (816, 618) of determining a remaining thickness of the second material by a recurrent analysis using the old etch quantity of the second material obtained by step c); and

e) a step of performing etching by changing an etching condition when the determined remaining thickness of the material reaches a predetermined value.

13. An apparatus for measuring a film process quantity in a semiconductor device manufacturing process, comprising:

a unit for setting standard patterns of differential values of interference light from a first material to be processed (4, 5, etc.) that correspond to a predetermined film process quantity of the first material, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (4, 5, etc.) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter; and

a unit for determining a film process quantity (43) of the second material based on the standard patterns of the first material and the actual patterns.

14. An apparatus for measuring a film process quantity in a semiconductor device manufacturing process, comprising:

a unit for setting standard patterns of differential values of interference light from a first material to be processed (4, 5, etc.) that correspond to a predetermined film process quantity of the first material, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (4, 5, etc.) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

a unit for determining a film process quantity (43) of the second material based on the standard patterns of the first material and the actual patterns; and

a unit for performing processing by changing a process condition when the film process quantity of the second material reaches a predetermined value.

15. An apparatus for measuring an etch quantity of a material being processed, comprising:

a unit for setting standard patterns (P_S) of differential values of interference light from first material to be processed (4) that correspond to a predetermined etch quantity of the first material including a mask layer (41), the standard patterns using the wavelength as a parameter;

a unit for setting standard patterns (P_M) of differential values of interference light from the mask layer of the first material that correspond to a predetermined etch quantity of the mask layer, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (4) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter; and

a unit for determining an etch quantity (44) of the second material based on the standard patterns of the first material, the standard patterns (P_S and P_M) of the mask layer, and the actual patterns.

16. An apparatus for measuring an etch quantity of a material being processed, comprising:

a unit for setting standard patterns (P_S) of differential values of interference light from a first material to be processed (4) that correspond to each of a plurality of predetermined etch quantities of the first material including a mask layer (41), the standard patterns using the wavelength as a parameter;

a unit for setting standard patterns (P_M) of differential values of interference light from the mask layer of the first material that correspond to each of a plurality of predetermined etch quantities of the mask layer, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (4) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

a unit for determining an etch quantity of the second material based on the standard patterns of the first material, the standard patterns (P_S and P_M) of the mask layer, and the actual patterns; and

a unit for determining an etch quantity (S, M) of the second material at a present point in time by a recurrent analysis using the determined old etch quantity of the second material.

17. An apparatus for measuring an etch quantity of a material being processed, comprising:

a unit for setting standard patterns (P_Z) of differential values of interference light from a first material to be processed (5) that correspond to each of a plurality of predetermined etch quantities of the first material, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (5) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

a unit for determining an etch quantity of the second material based on the standard patterns of the first material and the actual patterns; and

a unit for estimating a time at which the etch quantity of the second material reaches a target value, by a recurrent analysis using the determined old etch quantity of the second material.

18. The etch quantity measuring apparatus according to claim 17, further comprising:

a unit for determining an initial thickness and a remaining thickness of the second material by a recurrent analysis using the determined old etch quantity of the second material; and

a unit for determining an etch depth of the second material based on the initial thickness and the remaining thickness of the second material obtained.

19. An apparatus for processing a material in semiconductor devices having a plurality of stacked films, comprising:

a unit for measuring a remaining thickness of the material being processed; and

a unit for performing etching by changing an etching condition when the remaining thickness reaches a predetermined value.

20. An apparatus for etching a material in semiconductor devices having a plurality of stacked films, the material being formed over an underlying film having parts of different thicknesses, the etching apparatus comprising:

a unit for measuring a remaining thickness of the material formed over the thick part of the underlying film; and

a unit for controlling the etching according to the measured remaining thickness of the material.

21. The etching apparatus according to claim 20, further comprising:

a unit for performing etching by changing an etching condition when the measured remaining thickness of the material reaches a predetermined value.

22. An apparatus for etching a material in semiconductor devices having a plurality of stacked films, comprising:

a unit for setting standard patterns (P_Z) of differential values of interference light from a first material to be processed (7) that correspond to each of a plurality of predetermined etch quantities of the first material, the standard patterns using the wavelength as a parameter;

a unit for measuring intensities of interference light of multiple wavelengths from a second material being processed (7) of the same structure as the first material and determining actual patterns of differential values of the measured interference light intensities, the actual patterns using the wavelength as a parameter;

a unit for determining an etch quantity of the second material based on the standard patterns of the first material and the actual patterns;

a unit for determining a remaining thickness of the second material by a recurrent analysis using the old etch quantity of the second material obtained by step c); and

a unit for performing etching by changing an etching condition when the determined remaining thickness of the material reaches a predetermined value.